This invention relates to viscosity increasing agents. More particularly, this invention relates to gum particles usable as thickeners, gel forming agents or suspending agents.
Xanthan gums are well known thickeners or gel forming agents. See, for example, Jordan, U.S. Pat. No. 3,748,201; Sullivan, U.S. Pat. No. 3,944,427; Karl, U.S. Pat. No. 4,038,206; Gunn, U.S. Pat. No. 4,052,231 and Germino, U.S. Pat. No. 4,059,458. Difficulties have been encountered in utilizing gum particles to thicken or gel aqueous media. Uniform distribution of the agent throughout the medium is ordinarily desired. However, when the gum particles are added to an aqueous medium, the particles may start to set or gel at the point of addition before they have been uniformly dispersed throughout the entire medium. Even if gelation does not occur at the point of addition, the added gum particles often agglomerate or form clumps which will not dissolve as intended in the medium. High shear mixing for extending periods has been required to disperse the thickener throughout the medium, and even that has not always proved satisfactory.
Various types of approaches have been attempted in order to overcome such problems including coating the gum particles with highly soluble protective coats. For example, Rigler in his U.S. Pat. No. 3,928,252 teaches incorporating a bicarbonate and an organic acid which will react to form carbon dioxide in a thickening material in order to prevent clumping of the material upon addition to an aqueous medium. Gukenberger, U.S. Pat. No. 3,850,838 teaches agglomeration of gum thickner particles with a carbohydrate binder such as sucrose, dextrose or corn syrup solids in order to improve the dispersability of the particles in an aqueous media. Similarly, Sprayberry in his U.S. Pat. No. 3,551,133 discloses coating gum particles with molasses in order to improve dispersability and prevent clumping. Procedures such as these leave somewhat to be desired because the materials with which the gum particles are treated may not be acceptable in compositions where it is desired to use the gum particles, particularly in food compositions where taste considerations are paramount or in low calorie food preparations.
Insoluble or sparingly soluble fat derivatives have been utilized in compositions for coating highly soluble hygroscopic salts in order to retard take-up of atmospheric moisture and consequent caking of the salts. See: Kell, U.S. Pat. No. 2,175,083; Strashun, U.S. Pat. No. 2,557,155; Otrahalek, U.S. Pat. No. 3,301,636; Allan, U.S. Pat. No. 3,082,154 and Block, U.S. Pat. No. 1,793,420. It has also been known in the art to use surfactants to enhance the solubility of various water-soluble materials. See: Jolly, U.S. Pat. No. 3,657,182 and Procyk, U.S. Pat. No. 3,755,529.
Despite all the efforts of the prior art, there has remained a need for a delayed action viscosity increasing agent which would also be nonclumping.